Astronomy Week comes to a climax next weekend with Astronomy Day — but astronomical societies around the country are scheduling special events throughout the week, not just on the big day. Check out the Astronomical League's state-by-state list for an event near you.

Even if the skies are cloudy, you can enjoy the wonders of the Web: As I mentioned last week, the Space Telescope Science Institute is putting on a trivia contest that capitalizes on its "Way Out" online game. You can also keep posted on Comet Bradfield's progress via the Solar and Heliospheric Observatory's Web site, and watch Cassini's progress toward Saturn on the CICLOPS Web site.

If your night skies are obscured by city lights, click on over to the International Dark-Sky Association to learn more about light pollution — and how to fight it. Manufacturers are getting more savvy about designing lamps that light up the streets while keeping the skies darker. One example is the InVUE line made by Cooper Lighting, which uses special shielding and optics to minimize the skyward glare.

The concept of "Dark Sky Compliant" lighting is still somewhat controversial, particularly in a security-conscious age like the current one, but cutting down on needless light pollution is a noble cause that deserves recognition during the coming week.

• April 16, 2004 | Updated 7:30 p.m. ETMartian code cracked: When the Spirit and Opportunity rovers landed on Mars three months ago, they were carrying two secrets: encoded messages that were printed on mini-DVDs attached to each of the spacecraft. The secret code was part of a game organized by the Planetary Society as part of its "Red Rover Goes to Mars" educational effort, sponsored by Lego.

More than 2,000 entrants deciphered at least one of the coded messages, and the first one to crack both codes was Jim Gillogly of Westwood, Calif.

"The Spirit cipher took me a good while," Gillogly, a cryptographic systems programmer, told the Planetary Society. "I spent about two hours before the first clue, then another four or five hours before the second clue, and about half an hour after the second clue. That broke it open for me. The Opportunity cipher took about 10 minutes total."

The Planetary Society is awarding Lego prizes and society memberships to the first 10 people who successfully broke each code as well as to 30 random winners selected from all of the cryptographers who submitted correct answers. You can still try your hand at breaking the Spirit and Opportunity codes, or if you're impatient with puzzles, as I am, you can follow the Planetary Society's link to the solutions.

• April 15, 2004 | 6:10 p.m. ETSpace race update: The international drive to put regular folks in outer space is moving ahead in four countries: the United States, Canada, Russia and ... Brazil? Here's a quick roundup:

SpaceShipOne (U.S.): Scaled Composites released a short burst of data from last week's
second supersonic flight
of SpaceShipOne, its privately funded suborbital space plane. Only one departure from the flight plan was noted: "A planned immediate motor ignition was delayed about two minutes to evaluate a shock-induced stall buffet," the status report says. But everything else was nominal, as they say in the business, and the team acquired "spectacular footage" of the flight.

Da Vinci Project (Canada): An article today in the British newspaper The Guardian touts the Da Vinci Project as the "dark horse" in a two-horse race for the $10 million X Prize. Like Scaled Composites, the Da Vinci team is aiming to win the prize by launching its suborbital space vehicle twice in a two-week time frame this year. If the Da Vinci team gets the go-ahead from Transport Canada, it may have an edge; the SpaceShipOne team reportedly has to give official notice of a launch attempt as much as 90 days in advance. Da Vinci team leader Brian Feeney told The Guardian that he would consider moving up his launch date to go first.

Space Adventures (Russia): Self-funded space explorer Greg Olsen, who's
paying millions
for a flight to the international space station, went through his official introductions at Russia's Star City cosmonaut center on Wednesday and began his training, according to Virginia-based Space Adventures and Russia's RIA Novosti news service. Russian reports indicate the earliest he'll fly is next April. For updates on Olsen's odyssey, check GOToOrbit.com (GO stands for Greg Olsen ... get it?).

Space Adventures (Brazil): Space Adventures announced today its participation in a sweepstakes sponsored by Volkswagen of Brazil. Among the 11 prizes offered will be zero-gravity airplane flights and suborbital space flights — but if you win a suborbital seat, you might have to wait until the craft actually becomes available (see X Prize, above). "Through these flights and our other programs, we at Space Adventures continue the ongoing effort to open the space frontier to private citizens," Eric Anderson, the company's president and chief executive officer, is quoted as saying. Boa sorte to our friends in Brazil.

• April 14, 2004 | 3:30 p.m. ETHow much does Mars cost? Is it $3 million a day, or $100,000 a day? When you're talking about the cost of the current Mars Exploration Rover missions, you could make a case for either figure.

The $3 million figure is the one I started out with in my story about
one day in the life of the Mars rovers
— calculated in about the crudest way one could imagine. For the dollar part of the equation, I just took the original mission cost of $820 million and added the $15 million that was budgeted
just last week
. For the duration, I added together the 90-day primary mission and the roughly 150-day extended mission. Divide the dollars by the duration, and you get about $3.6 million a day.

That's how a Broadway producer might eyeball the cost of putting on a show like, say, "The Producers," but does that really tell you how much money is spent during one day of operations on Mars? Absolutely not, as Steve Schnider pointed out in a follow-up e-mail:

"Spreading NASA's budget for the two rovers over the projected lifespan of the project to come up with a daily cost is a very faulty and misleading way to represent the operating cost of the rovers.

"The cost of robotic space exploration is not incremental. In fact, the bulk of the $835 million (I've seen a variety of numbers for this) is spent upfront in the design, construction and testing of the rovers, the launch vehicle and the ground support. If one or both of the rovers had failed at some point in their journey, most of that budget would still have been gone. It's not being there that is costly, it's getting there.

"The factual way to represent this is the high cost of getting there and the minimal cost of being there. So in truth, the real picture is, that the rovers are costing practically nothing to produce science on a distant alien world."

When you look more closely at the $820 million, you find that $645 million went for development of the spacecraft and scientific instruments, $100 million for launch and just $75 million for mission operations and science data processing. When you consider that $15 million covers another 150 days or so, you get an even better idea of the bargain: Each additional day of operation works out to just $50,000 per rover. Not a bad price for maintaining the machines as well as a mission team of more than 150 scientists and engineers.

There's another aspect of the Mars mission that I haven't mentioned in these calculations: the educational element. My guess is that millions have been spent to distribute all those pictures and data via NASA's Mars portal site on the Web, as well as via all the other outreach efforts involving schools and museums. One such effort is the Planetary Society's "Red Rover Goes to Mars" program — and another is "Rock Around the World," an effort involving NASA's Jet Propulsion Laboratory and Arizona State University.

Tim Trumble
/
Arizona State University

Arizona State University's Phil Christensen, a member of the Mars mission team, is surrounded by boxes full of rocks that students have mailed in for analysis, as part of the "Rock Around the World" program.

The geologists behind "Rock Around the World" invited kids to collect rocks and send them in for analysis, using a spectrometer much like the Mini-TES employed by the Mars rovers. If anything, the program has been too successful: More than 3,700 rocks have been received from all 50 states and 20 countries. And rocks aren't the only things being sent in, said Phil Christensen, an ASU planetary scientist and a member of the rover science team.

"We've received some 10-page reports and CDs full of information," Christensen said in a news update on the project. "Some of these kids have gone totally out of control."

The way Christensen sees it, that's a good thing.

“It's gratifying to see kids get excited about Mars science — the geology and the physics of how we do analysis, not just the gee-whiz ‘exploring space' stuff,” he said. “I think for some of these students, this may be the beginning of a career in earth sciences.”

If you have long-simmering questions for the Mars mission team, here's your chance: We're taking requests from MSNBC.com users, and we'll pass along a selection of the questions to team members at NASA's Jet Propulsion Laboratory. Stay tuned for the answers next week.

The cost-of-Mars question is more complex when it comes to future missions: Would it cost a
trillion dollars
to get humans to the Red Planet via the moon? $20 billion for the Mars Direct option? Or just
$3.5 billion
? How much would you be willing to pay, for what kind of Mars mission? Let me know what you think.

• April 13, 2004 | 7:45 p.m. ETInvisible fireworks revealed: The latest picture from NASA's Spitzer Space Telescope features a celestial fireworks show that could be seen only with infrared eyes.

The dusty haze surrounding the stellar nursery in the constellation Cygnus, known as DR21, is so thick that it blocks light in visible wavelengths. But the blazing stars still make their presence known by giving off dust-penetrating infrared radiation — and seeing things in that part of the spectrum is Spitzer's specialty.

The biggest stars are thought to be 100,000 times as bright as our own sun, the team reports in today's Spitzer update. All that power is blasting away ferociously at the surrounding haze.

"We've never seen anything like this before," said William Reach, an investigator for the latest observations and an astronomer at the Spitzer Science Center at the California Institute of Technology. "The massive stars are ripping the cloud of gas and dust around them to shreds."

NASA / JPL / Caltech / ESTEC / ESA

In this composite image of DR21, the different colors represent different wavelengths, including visible light as well as infrared. Click on the image to see larger views.

Before Spitzer turned its attention to DR21, the most that astronomers could see in radio and infrared wavelengths was a powerful jet emanating from the cloud. That turned out to be just "the tip of the iceberg," the center says.

In Spitzer's false-color view of the scene, a dense knot of massive stars can be seen surrounded by a wispy cloud of gas and dust. Red filaments containing organic compounds called polycyclic aromatic hydrocarbons stretch across the cloud. A green jet represents fast-moving, hot gas being ejected from the region's biggest star.

"Below DR21 are distinct pockets of star formation, never captured in full detail before," the center says. "The large swirling cloud to the lower left is thought to be a stellar nursery like DR21's, but with smaller stars. A bubble possibly formed by a past generation of stars is visible within the lower rim of this cloud."

• April 13, 2004 | 7:45 p.m. ETSpace stations for the next generation: The winners of last year's World Space Week competition were announced today in Los Angeles — and 'N Sync pop star
Lance Bass
, who lent his name to the "Lance's Lab" space station design project, was suitably impressed.

"When we asked kids to come up with ideas that could one day become working components of a space station, we fully expected to receive some outstanding projects," Bass, World Space Week's youth spokesman, was quoted as saying in the announcement. "But I was amazed at the level of complexity and detail they came back to us with. Many of these proposals had concepts I had never even heard of, and a few sounded like they came directly from a NASA engineer's drawing board."

Winners were named in three categories — for teams from elementary schools, middle schools and high schools. In addition, Shelly Clark, a fifth-grade teacher at Langston Magnet School in Hot Springs, Ark., was awarded a teacher grant. Clark was a student of Christa McAuliffe, the teacher who lost her life in the 1986 Challenger tragedy. Today, Clark was commended for helping her class cope with last year's Columbia tragedy.

You'll find the full list of winners at the World Space Week Web site. Planning is already under way for the next World Space Week competition, which involves creating zero-gravity sports that could be played in orbital arenas. This contest ties in with the Space Island Group's plan to create commercial facilities in low Earth orbit within the next decade.

On April 12, 1961, Soviet cosmonaut Yuri Gagarin blasted off from Kazakhstan and made one orbit of the earth, setting the stage for a decade-long space race.

Gagarin was 27 years old — and tonight, the 74 "World Space Parties" scheduled in 34 countries cater particularly to folks just about that age. The party agenda includes music, merriment and making the acquaintance of cosmic VIPs.

This is an especially good year for the Yuri's Night spirit: If he were still alive, Gagarin would have turned 70 this year and could still have hoped to go into space again (after all,
John Glenn
did at the age of 77). Last October, China had its own
Yuri Gagarin moment
, and later this year we may see an astronaut take a suborbital ride on the first
privately funded spacecraft
.

As Gagarin himself said, "Poyekhali!" ... "Let's go!"

• April 12, 2004 | 3:30 a.m. ETGone again: I'll be out of the office for a few days, so the Log postings won't be quite as voluminous as usual.